The original API returned either an ERR_PTR() or a refcounted sdev.
Unfortunately, if it's successful, you need to do a scsi_device_put() on
the sdev otherwise the refcounting is wrong.

Everyone seems to expect that scsi_add_device() should be callable
without doing the ref put, so alter the API so it is (we still have
__scsi_add_device with the original behaviour).

The only actual caller that needs altering is the one in firewire ...
not because it gets this right, but because it acts on the error if one
is returned.

Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

On some platforms the hard-casting of 8 byte node_name and
port_name arrays to an u64 would cause unaligned-access
warnings.  Generalize the conversions with a transport
helper function which performs consistent shifting of WWN
bytes.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

The SAS transport class contains common code to deal with SAS HBAs, an
aproximated representation of SAS topologies in the driver model,
and various sysfs attributes to expose these topologies and managment
interfaces to userspace.

In addition to the basic SCSI core objects this transport class introduces
two additional intermediate objects:  The SAS PHY as represented by struct
sas_phy defines an "outgoing" PHY on a SAS HBA or Expander, and the SAS
remote PHY represented by struct sas_rphy defines an "incoming" PHY on a
SAS Expander or end device.  Note that this is purely a software concept, the
underlying hardware for a PHY and a remote PHY is the exactly the same.

There is no concept of a SAS port in this code, users can see what PHYs
form a wide port based on the port_identifier attribute, which is the same
for all PHYs in a port.

This submission doesn't handle hot-plug addition or removal of SAS devices
and thus doesn't do scanning in a workqueue yet, that will be added in
phase2 after this submission.  In a third phase I will add additional
managment infrastructure.

I think this submission is ready for 2.6.14, but additional comments are
of course very welcome.

I'd like to thanks James Smart a lot for his very useful input on the
design.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

This one removes struct scsi_request entirely from sd.  In the process,
I noticed we have no callers of scsi_wait_req who don't immediately
normalise the sense, so I updated the API to make it take a struct
scsi_sense_hdr instead of simply a big sense buffer.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

This one's slightly more difficult.  The transport class uses
REQ_FAILFAST, so another interface (scsi_execute) had to be invented to
take the extra flag.  Also, the sense functions are shifted around to
allow spi_execute to place data directly into a struct scsi_sense_hdr.
With this change, there's probably a lot of unnecessary sense buffer
allocation going on which we can fix later.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

After this, we just have some drivers, all the ULDs and the SPI
transport class using scsi_wait_req().

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>